Portable storage system and method thereof

ABSTRACT

The present invention discloses a portable storage system and method thereof used in a computer system. The present invention makes it easy to remove a mass storage device from a computer system without bumping against the operation system (OS). The portable storage system comprises a mass storage device, a processor, a first memory and a second memory. When a user removes the mass storage device from a computer system, the present invention can simulate a response to the OS in order to prevent the OS from shutting-down which will be caused if the OS cannot sense the existence of said mass storage device.

FIELD OF THE INVENTION

[0001] The present invention relates to a portable storage system, moreparticularly, to transform the mass storage device of a computer into aportable storage system.

BACKGROUND OF THE INVENTION

[0002] In the modem Internet age, mass information needs to bedigitalized to proceed and store, and transmitted by computer. Thus theneed for huge volume, high speed, portable and stabile recording mediaand storage devices for reading and writing the digitalized informationis appreciated. Historically, portable storage systems have mostly usedfloppy disks; therefore the volume was greatly restricted. Recently,large volume portable storage systems such as CD-ROM or MO have beeninvented to provide greater storage capacity. However, because of theirexpensive price, consumers cannot afford to have such a portable storagesystem.

[0003] Presently, the cheapest and most convenient storage system is thehard disk. It does not have portability due to the restrictions of itsdesign. Then, a removable box is designed to allow the hard disk to beeasily removed from a computer. However, when we put a hard disk insidethe removable box, we still cannot remove the hard disk from a computerwhile the computer OS is in operation. A function which we call a hotplug, allows users to remove disk units from a computer without turningoff its power. Without this hot plug function, once the hard disk isremoved from the computer, the OS will shut down because the CPU cannotsense the proper response of said hard disk. In addition, the use of aremovable box often causes damage and instability to the computersystem.

[0004] The Redundant Arrays of Inexpensive Disks (RAID) was proposed inthe essay published by Patterson, Gibson and Katz of University ofCalifornia at Berkeley, U. S. A. in 1987. RAID discloses the design ofseveral disk arrays, whose purpose is to incorporate a plurality ofsmall and inexpensive disks into a disk array. The performance of thisdisk array is better than some large but expensive disks. Furtherbenefits of RAID includes such as: in spite of the combination of aplurality of disks when using RAID, it remains a single memory storageunit to the computer system using said RAID. RAID not only makes abackup easily, by a repetition storage method to implement thefault-tolerance function, but also has an easily removable feature tofacilitate maintenance. Thus, a user can replace the broken disk withoutremoving the whole disk system from the computer system. In order to getthis function, RAID usually employs a removable box for the moduledesign. This method puts each disk into a removable box from which thedisk can connect to the computer system. This method also protects therefined structure of the disk (especially the hard disk.) However, ifthe conventional RAID design of the removable box supports the hot plugfunction, the main body of the RAID will also have a lock on eachremovable box to prevent the system from breakdown due to the plugaction disrupting the connection of the disk in operation. With theincrease in the number of the disk units being used in importantapplication fields such as RAID of the telecommunication bureau, wherethe number of the disks is usually more than 100-200. If we try toreplace one of the disks, it is very easy to cause the breakdown of thewhole system because of difficulty of locating the disk to be replacedor due to the negligence of the computer operator. When there systembreakdown, the transactions and services of the enterprise will beinterrupted and important data will be lost. If, we sacrifice theconvenience of hot plug function of the RAID to avoid the aboveproblems, the RAID will become acceptable because of inconvenience anduselessness.

SUMMARY OF INVENTION

[0005] The primary object of the present invention is to provide aportable storage system for a computer system. The portable storagesystem comprises a mass storage device, a processor, a first memory anda second memory. The system can simulates an appropriate response to arequest from the OS when the mass storage device is removed from thecomputer. To simulate the existence of said mass storage device, themass storage device can be provided with the hot plug function. Thus, auser can remove a mass storage device from a computer system at any timeand use said mass storage device as a portable storage medium.

[0006] In addition, the present invention also provides an operationmethod of a portable storage system. Thus, a mass storage device (suchas a hard disk) can be transformed into a portable storage medium.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]FIG. 1 shows a basic structure block diagram of the presentinvention and how to connect it to a computer according to an embodimentof the present invention.

[0008]FIG. 2 shows the simulation of a hard disk to provide a responseto the operation system in an embodiment of the present invention.

[0009]FIG. 3 shows the flow charts of the method of an embodiment in thepresent invention.

LIST OF REFERENCE NUMERALS

[0010] (11) IDE bus

[0011] (12) Buffer cache memory

[0012] (13) EEPROM

[0013] (14) Processor

[0014] (15) IDE Disk 1

[0015] (16) IDE Disk 2

[0016] (21) IDE bus

[0017] (22) Buffer cache memory

[0018] (23) Buffer cache memory

[0019] (24) Mechanism Task

[0020] (25) Mechanism Task

[0021] (26) Physical data

[0022] (27) Physical data

[0023] (28) Processor

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0024] The present invention provides a portable storage system for acomputer system, which comprises a mass storage device; a first memoryfor buffering and storing the data necessary for responding to theinstructions issued by the computer system to said mass storage device;a processor for receiving the instructions from the computer system tosaid mass storage device and responding preliminarily via said firstmemory to said computer system; and a second memory for storing programsnecessary for the actions of the processor.

[0025]FIG. 1 is an embodiment of a portable storage system, used in suchas a personal computer system, according to the present invention. Theportable storage system comprises hard disks (15,16), a processor (14),a buffer cache memory (12) and an EEPROM (13). The system simulates anappropriate response to a request from the OS when the hard disk isremoved from the computer. By simulating the existence of said harddisk, we can provide the function of a hot plug for all of the harddisks. Thus, a user can remove a hard disk from a PC at any time and usesaid hard disk as a portable storage medium. FIG. 1 provides a basicconnection relationship of the present invention and IDE bus (11) withhard disks (15,16) of the computer system.

[0026]FIG. 2 shows the working theory of the portable storage system ofthe present invention, wherein a processor (28) is used for monitoringthe hard disks (15,16) connected to the IDE bus. The system simulates anappropriate response to a request from the system CPU when the hard diskis removed from the computer. By simulating the existence of said harddisk, a user can remove a hard disk from a computer when the OS is inoperation and thus, we can provide the function of a hot plug for all ofhard disks. FIG. 2 shows how the embodiment of the present inventionsimulates the action as if the hard disk still exists and read/write thephysical data (26,27) and performs the mechanism task (24,25) by abuffer cache memory (22,23). When the OS seeks a response from the harddisk which was removed, the processor (28) provides an appropriateresponse via said buffer cache memory (22,23) to prevent the system fromshutting-down which will be caused if the OS cannot detect the existenceof said hard disk.

[0027] Before the present invention, the way of responding thenonexistence of a hard disk by the OS is to determine the condition ofthe hard disk first. If said hard disk is not existed and cannot providean appropriate response to the OS by a processor, the OS will be halted.Sometimes it will in result in the failure of a computer system.

[0028] If we can provide a response to the OS by a processor when thehard disk is not existed, then when a user reads/writes data to saidhard disk, the processor will respond that the hard disk is notavailable. Thus, it will prevent the computer system from shutting-down.

[0029] In addition, the present invention also provides an operationmethod of a portable storage system. First, a processor receives theinstructions of OS to a mass storage device; then, said processor willcheck the existence of said mass storage device and transmit the resultsto said OS via a buffer cache memory as a response. If said mass storagedevice is existed, said processor will perform the instructions of saidOS on said mass storage device. In another embodiment of the presentinvention, if said response notes that said mass storage device is notexisted, said OS will show the information of unavailability of saidmass storage device on the display screen.

[0030]FIG. 3 shows the steps of the method using in an embodiment of thepresent invention. First, in the initial state (300), the OS will readthe existence condition of the hard disks (310) and determine the harddisk, which will be removed, is existed or not. If said hard disk is notexisted, the processor in an embodiment of the present invention willgive OS a response that said hard disk is not existed (313). This willprevent the shutdown problem resulted from not responding to OS in theprior art. If said hard disk is existed, the processor in an embodimentof the present invention will give OS a response that said hard disk iscurrently available (311). At this time, the OS can read/write data tosaid hard disk.

[0031] Although the present invention has been disclosed in thepreferred embodiment, it is not used to restrict the present invention.It should be appreciated by persons skilled in the art that changes andmodifications may be made to the present invention without departingfrom the spirit and scope of the invention. Thus, the present inventionis protected by the appended claims.

REFERENCE

[0032] [1] Peter M. Chen, Edward K. Lee, Garth A. Gibson, Randy H. Katzand David A. Patterson, RAID: High-Performance, Reliable SecondaryStorage, ACM Computing Surveys, Vol. 26, No. 2, June 1994

[0033] [2] Chris Ruemmler, John Wilkes: An Introduction to Disk DriveModeling, IEEE Computer, Vol. 27, No. 3, March 1994

[0034] [3] D. A. Patterson, J.L. Hennessy: Computer Organization andDesign—The Hardware/Software Interface, Morgan Kaufinan, San Mateo,Calif. 1998

[0035] [4] D. A. Patterson, J.L. Hennessy: Computer Architecture—AQuantitative Approach, Morgan Kaufinan, San Mateo, Calif., 1990

What is claimed is:
 1. A portable storage system used in a computersystem, comprising: a mass storage device; a first memory for bufferingand storing data necessary for responding to the instructions of OS tosaid mass storage device; a processor for receiving instructions of OSto said mass storage device and responding preliminarily to said OS viasaid first memory; and a second memory for storing programs necessaryfor the actions of said processor.
 2. The portable storage system ofclaim 1, wherein the first memory is a buffer cache memory.
 3. Theportable storage system of claim 1 or 2, wherein the second memory is anEEPROM.
 4. A portable storage system used in a computer system,comprising: a hard disk; a first memory for buffering and storing datanecessary for responding to the instructions of OS to said mass storagedevice; a processor for receiving instructions of OS to said massstorage device and responding preliminarily to said OS via said firstmemory; and a second memory for storing programs necessary for theactions of said processor.
 5. The portable storage system of claim 4,wherein the first memory is a buffer cache memory.
 6. The portablestorage system of claim 4 or 5, wherein the second memory is an EEPROM.7. A method of operating a portable storage system, comprising thefollowing steps: receiving instructions of OS to a mass storage devicevia a processor; checking the existence of said mass storage device bysaid processor, and transmitting the results to OS via a buffer cachememory as a response; and if said mass storage device is existed, saidprocessor will perform the instructions of OS on said mass storagedevice.
 8. The method of operating a portable storage system of claim 7,wherein the response noting that said mass storage device is not existedwill cause said computer system to show on display screen theinformation that said mass storage device is not existed.
 9. A method ofoperating a portable storage system, comprising the following steps:receiving instructions OS to a hard disk via a processor; checking theexistence of said mass storage device by said processor, andtransmitting the results to OS via a buffer cache memory as a response;and if said mass storage device is existed, said processor will performthe instructions of OS on said mass storage device.
 10. The method ofoperating a portable storage system of claim 9, wherein the responsenoting that said hard disk is not existed will cause the computer systemto show on display screen the informaiton that said hard disk is notexisted.